IT executives are also concerned about the lack of representation of IT at board level - especially as most expect their budgets to stand still or decline during the next year.
Security has consistently been the top concern in BCS surveys over recent years, but in this year's poll of 390 BCS members who are IT managers or directors, 78% said quantifying the value of IT was their hot topic.
Sixty-one per cent of those polled mentioned security and 42% listed the lack of IT representation at board level.
The number of IT executives who expected their budgets to fall dropped to 37% from 48% a year ago. Just under 40% believed their budgets would remain the same as last year, and 20% expected them to fall.
Concern about the possible impact of static or declining budgets was highlighted by the finding that two of the top three factors seen as vital to competitiveness were the use of technology, mentioned by 43% of IT directors, and a strong investment strategy (37%).
Even so, these issues were some way behind the one that got the biggest response: 80% of IT executives said a professional skills set was essential.
Security continued to top the spending priorities, with personal computing, application software and mobile computing also featuring strongly.
"British companies clearly recognise the importance of leading-edge technology and strong technical and business skills in driving IT forward," said BCS chief executive David Clarke.
"We believe mobile computing technology, in particular, will play an increasing role in sharpening the UK's competitiveness in the global market.
"In addition, the survey underscores the importance of professional skills."
Government support for the IT industry has emerged as an increasing concern, drawing less appreciation than last year. Nearly 80% of IT managers felt that government investment in the sector was inadequate or not applied efficiently, compared with 74% last year.